The evolution of George Bush's persona over the past few weeks is startling for even the most casual observers. Only a short while ago, Bush was a strong, decisive leader and Kerry was a weak, flip-flopping Massachusetts liberal. The Bush campaign expected those images to carry them through the November elections: it had cost them more than $200m (£112m) to build those caricatures and they had every reason to expect a solid return on their investment.

But those images were built on a carefully crafted stage. Despite all the flaws in the US electoral process we still force the candidates to exit that bubble a handful of times during the election, and it is some credit to the system that those three 90-minute debates can still determine the fate of an election. This year, they have helped introduce the nation to Furious George.

Bush's political operators have worked overtime to make "angry" a pejorative term this political cycle. They wielded the "too angry" attack against Howard Dean in the primaries, when it seemed Dean would be the Democratic nominee, and it helped destroy Dean's candidacy. Republicans again shouted "too angry" to discredit Al Gore's series of impassioned anti-Bush speeches earlier this year.

The "too angry" claims successfully marginalised the content of those speeches - blistering indictments of an incompetent administration. But what happens when your best attack line is a double-edged sword?

Bush's operation has taken stage management to extremes. His handlers have figured - correctly - that the press conference format suits their man poorly and is to be avoided at all costs. His last primetime press conference was in April 2004, and he has had only two with the White House press corps since late August - both of them with the Iraqi prime minister, Ayad Allawi, at his side. (The Bush campaign actually wrote Allawi's speech in order to squeeze out precious political points.)

Bush's campaign appearances are not much better. While Kerry's events are open to the public, Bush's affairs require the signing of a "loyalty oath". Quietly wearing an anti-Bush T-shirt or badge is grounds for expulsion.

Bush faces only adoring audiences vetted by the campaign's enforcers. At his town hall events, questions are planted for maximum political effect. At one, a veteran merely got up and requested permission to salute his commander in chief. Compelling visuals? Perhaps. But it does little to acquaint Bush with reality.

Campaign commercials do their best to paint an alternative reality in which Bush is an effective leader and Kerry is anything but. Entire media networks, such as Fox News and Sinclair Broadcasting, prop up Bush in a way that would make their fellow propagandists in North Korea and Cuba proud. Sinclair, in fact, will pre-empt local programming on its 62 stations to air an anti-Kerry movie days before the election - unless a blog-led boycott forces a reversal.

Given the force of Republican efforts to deify Bush, his debate performances came as a big shock to many Americans. They showed a Bush quick to anger, indecisiveness, pettiness and petulance. The sheltered Bush was clearly unprepared for the debate and unprepared to face criticism. In fact, it seemed to take him by surprise. No one seemed to have told him he had critics.

After his first debate performance, Bush was in a quandary. He had to stem his erosion in the polls, but to do so would require attacking Kerry and furthering the perception that he was too angry to be president.

So how did he respond? By getting even more angry. He not only viciously attacked Kerry but also took out the moderator and several questioners in the process. Someone, somewhere, labelled Bush Furious George - a clever turn on HA Rey's Curious George children's books and an appellation that took firm hold in the online and, increasingly, offline worlds.

Bush acted like the proverbial ugly American trying to be understood in a foreign land, cranking up the volume and shrillness to make his points while Kerry sat by serenely. The contrast was impossible to miss as Bush became increasingly unhinged. Even on the road, Bush's desperation is palpable as the rhetoric soars to angrier heights.

Bush is now hemmed in. With poll after poll showing small Kerry leads, he needs to do something to regain the momentum. His campaign's attack ads have kept him in the game but he is not pulling away. Furthermore, he is well below the 50% mark in most key battleground state polls - a mark of political vulnerability.

If he cannot convince people to vote for him, he will have to convince people to vote against Kerry, and to do that he has to attack, attack, attack. And since it takes more skill than Bush possesses to attack without appearing angry, well, he's in a real bind.

Bush's political operation has conditioned the electorate to distrust "anger". It has made the charge a cornerstone of its smear effort against Democrats such as Dean and Gore. For a campaign that lives by the smear, it is poetic justice to see the tables turned. Furious George is here to stay.

· Markos Moulitsas runs the dailykos.com US political blog, and Our Congress, a blog tracking the hottest congressional races